Hottse electric



March 27, 1928.

A. H. CANDEE GAS ELECTRIC POWER SYSTEM Filed Feb. 19. 1927 2 0 H 5 a 6 M. 5 m m a m 6 Q m 5 0 4 5 5 "d 5 8 2 1 m. i M H C 6 7 j i g w i 8 7 7 2 2 L I 2 TM% M 46 INVENTOR AnarerW/Candee.

AT ORNEY WITNESSES: JWW- 2] 36/ Patented Mar. 27, 1928.

UNITED STATES PATENT OFFICE.-

ANDREW H. CANDEE, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR TO WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL VANIA.

GAS-ELECTRIC POWER SYSTEM.

Application filed February 19, 1927. Serial No. 169,523.

Thisinve'ntion relates generally to gaselectric power systems, and more part1cularly to the means for, driving the air compressors or other auxiliary devices provided 6 in such power systems.

The object of the invention, generally stated, is the provision of a 7 compressor drive for gas-electric power systems, that shall be simple and eflicient in operation,

:1 nd readily and economically manufactured.

A more specific object of the invention 1s 'to provide for the operation of an airv compressor, or any other auxiliary device, at the desired speed to effect its eflieient functioning at diflierent engine speeds, thereby to assure the air supply required for braking purposes.

Another object of the invention is to proride for the selective connection to the .20 generator of motor windings that are designed for operation at different voltages when the generated voltage varies because of changes in the engine speed.

Other objects of the invention will, in part, be obvious and, in part, will appear hereinafter. v I I The invention accordingly is disclosed in the embodiment thereof shown in the accompanying drawing, and comprises the features of construction. combination of elements, and arrangement of parts which will be exemplified in the construction hereinafter set forth. and the scope of the application of which will be indicated in the claims.

For a general understanding of the nature and objects of the invention. reference should be had to the following detailed description. taken in conjunction with the accompanying drawing, in which;

Fig. 1 is a diagram of the main-circuit connect-ions of a gas-electric power system arranged in accordance with this invention; and

Fig. 2 is a diagram of control circuits connected in accordance with this invention for governing the operation of the different units of the power system.

Referringnow to the drawing, an internal combustion engine 10 of any suitable type may be used as the prime mover of a gaselectric power system for propelling railway vehicles or the like- As is usual practice, the speed'of internal combustion engines is controlled by. regulating the fuel'supply and, in 'thisparticular embodiment of the invention, a throttle 11 is provided for controlling the fuel supply to the engine 10; In order to facilitate the operation of the throttle 1 1, an actuating lever 12 is disposed inf a, posi-' tion accessible to the operator and connected to the throttle 11 by means of a rod 13.

As will be observed, a generator 14, provided with an armature 15 and a shunt field winding 16, is directly connected to the engine 10 through a shaft 17. In this particular embodiment ofv the invention, the generator 14 that is utilized is of the shunt ype. a y In order to provide for theenerg ization of the generator. 14, an exciter 18 having an armature 19, a shunt field winding 20, and a differential field winding 21, disposed with the armature 19 connected across-the generator field winding 16. As i will 'be noted, the shunt field winding 20 of the eXciter is connected across a storage battery 22, while the differential winding 21 is connected in seriesrelation with the armature 15 of the generator 14. -Control of the circuit. for energizing the shunt field winding may be effected by means of either a manually operable switch 23, or an electro-magnetic switch 24. the operation of which will be referred to hereinafter.

The generator 14 may be utilized for supplying power to the propelling motors 25 and 26 of the power system. It will be noted that the motors 25 and 26 are of the series type and disposed to be connected in series or parallel relation by means of electro'magnetic switches 27. 28 and 28'. While the use of a plurality of propelling motors and means for connecting them for. operation in series and parallel relation is not essential to the operation of the invention to be described hereinafter, they are illustrated and described because it is with such propelling units that the invention will be generally used.

When the gas-electric power system is utilized for propelling railway vehicles, some means is ordinarily provided for operating an air compressor to provide the supply of compressed air required for the operation of the brakes. l n gas-electric power systems of this kind, the most convenient method of actuating an air con'ipressor is to utilize an electric motor that may be energizedfrom the main generator.

A's will he readily understood, when a gas electric power system is utilized in railway work, the supply of corrrpressed-air "maybe conie excessively diminished because of braking operations, or 'fonother reasons, either when .the gas-electricengine is operating at rated speed and moving the vehicle, or at idling speed whilethe vehicle is at rest. In many instances the failure of .the air supply is caused by the difference between the idlingspeed and the ratedspeed of the internal combustion engine, which difierenee is great enough to cause a drop in the voltage developed by the generator that is sutticient to interfere with the etticient operation of the compressor.

In heavy types of gasoline engines that might be used for. such purposes as operating a train, the idling speed-of the engine-is sometimes as low. as 250 R. P. M., while the rated speed may be approximately 1100 R. P. M. The voltage developed by the generator under constant load conditions will vary directly as the speed of the engine. Therefore, at idlingspeed the voltage wouldwnot be sufficient to efliciently operate a compressor motor designed tooperate on the normal voltage of the generator.v

Inorderto providefor the efficient operation ofthe compressor from the internal combustion engine of a gas-electric power system, the presentinvention was introduced. In this embodiment of the invention, a motor shown generally at 29 is provided with two sets of windings, one adapted for operation at high voltage or at the voltage developed by the generator 15 when the internal con'ibustion engine 10 is running at its rated speed and load, and the other a set of low-voltage windings adapted to operate etticiently at the voltage developed by the generator when the engine 10 is idling. The set of high-voltage windin includes an armature 30 and a series eld winding 31, while the set of low-voltage windings comprises an armature 32 and series field winding 33. As will be observed, the armatures 30 and 32 are mounted on a common shaft 34, which is disposed to drive an air compressor 35.

VVhile,. in this embodiment of the invention, a. single motor provided with highvoltage and low-voltage windings is utilized for operating the air compressor, it .will be readily understoodthat two separate motors might be substituted. However, it is pointed out that the use of the separate motors is more expensive and requires a greater amount of floor space, which in trains driven by gas-electric power systems is an important item.

WVlien a/Tailway vehicle of why kind is provided with airbrakes, they cannot be etticicntly operated directly from the compressor. Consequently, insthis construction, an airstorage' reservoin 36 conneoted to the com ressor 35 by a pipe 37 is provided.

T e control -system provided for governin the operation of the main vehicle-propelling motors'25 and 2G, and the compressor motor 39 will now be described. Since .the motors 25 and .26 aremerelyiincideutal' to my present system, their operation I will not be set forthingreatdetaiL I,

Assume now that the internal combustion engine 10 has been set in operatio tand that it is turning over at idlin speed? In order to excite the generator fie dgvinding 16, the switch 23'is firstclosed energizing the actuating coil' of the switch As will be .observed, when the-,swit'cli23 is closed, current flows from the battery 22 through conduc tors 38, 39 and40, the governor switch t1, conductor 42, contactplate 43.0f a' double toggle switch 44, conductor 45, actuating C011 oflswitc-h 24', and conductors 46 and 47 back to the batteryi' 'Tlie closure of the switch,24 establishes jdycircuit for the exciter field wi ndi n '20, an d current fflo ws from battery 22 ,t trough conductors. 38 and 39,

exciter field winding 20, conductor 48, switch 24; and conductors 49 and 47 back to the battery. A I

-The exciter'flS now develops avoltage, and current flowsjroin tlie e xciter armature 19 throughcoiiductors 50 and 51, the generator shunt field winding lti and conductors 52. 53 and 54: back to. the armatureot the excite r. Whenthe generator field winding is thus excited, a voltage is built up in the armature .15.and impressed'across the line wires55 and 56. Since the internal combustionengine 10 is operating only at idling speed, the generator will not build up normal rated voltage.

In order to rovide tor the charc in' ot I 4 t P! the storage battery 22, it connected across the armature 19 of the exciter. Consequently, when the; exciter is operated at rated speed, it-will function to charge the, battery 22. It will be readily understood that the customary charging regulators may he interposed between the exciter and the battery.

When the engine 10 is accelerated by the actuation of the throttle l1, the generator 14 will buildup the voltage required for the operation of the motors 25 and 26,.this volt.- age being, controlledto some extent by the current flowing in the differential field winding 21. Inordertoprovide for the proper connections between generator 14 and motors 25 and 26, to effect rotation of the latter in the desired direction, a master reverser switch 57, which controls the setting of the revcrser drum 58, is utilized. Since-switch ing devices suitable for mounting on the reverser drum 58 and adapted for reversing motor connections are well known it is considered unnecessary to illustrate'them.

The master reverser switch 57 comprises two contact segments 59 and 60, the former being disposed to engage cont-act'fingers 61 and 62, while the latter is positioned to engage contact fingers 62 and 63.

Assume now that it is desired to rotate the motors 25 and 26 in a forward direction, that the master reverser switch 57 is actuated to project the contact segment 59 into engagement with the Contact fingers 61 and 62 and that the toggle switch 44, which is disposed for actuation in eonjunction with the throttle 11','has been operated to place the contact plate 43 in engagement with the contact fingers 64 and 65. It may alsobe assumed that the manually operable switch 66 has been actuated to provide for the series connection of the motors 25 and 26.

A circuit is now established -whieh may be traced in Fig. 2 as extending from the energized conductor 39 through'conductor 101. contact fingers 100 and 99, bridged by contact plate 94, conductors 102, 45 and 67, contact fingers 64 and 65, bridged by contact plate 43, conductor 68 contact fingers 62 and 61, bridged by contact. plate 59, conductor 69, contact fingers 70 and 71, bridged by contact segment 72 of drum 58, conductors 73 and 74, switch 66, conductor 75, interlock 28-outprovided onswitch 28, and the actuating coil of the switch 27. Upon the clomre of the switch 27, the motors are connected in series relation and the motor circuit extends from the energized line conductor 55 through conductor 76, motor 25, conductor 77, switch 27, conductor 78 and motor 26, to the line conductor 56.

In order to operate the motors in parallel relation. the switch 66 is thrown to the right as illustrated in Fig. 2, and current flows from energized conductor 74 through switch 66, conductor 79, interlock 27-out and the parallehconnected actuating coils 28 and 28' to the negative conductor 46.

In this manner two parallel motor circuits a re established: one may be traced from line conductor 55 through conductor 80. switch 28 and motor 26 to line conductor 56, and the other through conductor 76, motor 2 5, switch 28' and conductor 81' to line conductor 56.

In order to explain the operation of the compressor motor 29, as the. engine 16 is started and accelerated to rated speed, let us again assume that the engine is operating at its idling speed. As will be readily understood, when it is desired to reduce the engine 10 to idling speed, the throttle 11 is actuated to decrease the supply of fuel. Since the toggle switch 44 is connected to the throttle 11, the operation of the latter to decrease the fuel supply serves to project the contact plate '43 into engagement with contactfingcrs 82 and 83.

The actuation of the toggle switch 44 establishes a new coil-energizing circuit for the'swit'ch 24. thus maintaining an energizing circuit for the exciter 18 and accordingly the generator 14. The snitch-actuating circuitn'ow established extends from energized conductor 39 through conductor 46, governor switch 41, conductor 42, contact fingers82 and '83, bridged by contact plate 43, conductor 45 and the actuating coil of; switch 24 tOthe-negatiVeconductor 46.

'Theiefoi'e,'as long as the switch 24 remains closed, a voltage is developed by the generator 14, and the line conductors 55 and 56"have a voltage impressed across them. However, since the engine is idling, the voltage impressed across the line conductors 55 and 56 is now insufiicient to actuate a voltage relay 84, which is disposed to control the actuating circuits of switches 85 and 86 provided for connecting the high-voltage and low-voltage windings, respectively, of the motor 29 across line conductors 55 and 56. Assume that the pressure in the reservoir '36 is low and that the governor switch 41 is closed. Current may now flow from energi zed conductor 40, through governor switch 41, conductor 87, contact fingers 88 and 89, bridged by a contact member 90 carried by .the'relay 84, conductor 91, contact fingers 92 and '93, bridged by contact plate 94 of the tOggIe sfw'Itch 44, conductor 95,,actuating coil of switch .86 and conductor 96 to the negative conductor 46, whereby the'switch 86 is closed. Y 4

In this manner the circuit for the set of low-voltage windings of the motor 29 is established and current flows from energized line conductor 55 through conductor 97, switch 86. the armature 32 and the series field winding 33 of the motor 29 and conductor 98 to line conductor 56. The low-voltage armature 32 now operates the compressor 35 and will continue to do so until the pressure in the reservoir 36 becomes great enough to operate the governor switch 41.

Upon the operation of the governor switch 41, the actuating circuit of the switch 86 is interrupted and the switch ispermitted to open, thereby interrupting the circuit of the low-voltage armature windings. However, it will be readily understood that if the engine continues to operate at idling speed, a drop in air pressure, causing the closure of the gtwernor switch 41, will eiiect a reestab lishment of the actuating circuit of the switch 86 and. thereby a re-connection of the low-voltage windings across the line conducso I tors .55. ltl'ltl '56 to again operate the compressor 35. v

'Asstune now that it is desired to operate the engine at rat-ed speed, and that the throttle L1 is actuated to increase the fuel supply. As .will be, readily understood,vthe opl'zllitm of the throttle etiect's upward movementof toggle switch 44;, thereby moving contact plate 43 into engagement with con tactfingtlS-S 64 and 5 and contact plate 94 intocngagcmcut with contact fingers 99 and 100.

, Tlheactuation oi thetoggle switch 44 to its uppeiyposition establishes an actuating circuit forzthc switch 24 which extends from positively energized conductor -39-. thr.ough condnctor wl, contactfingersl-OO and 9 9, bridged by-contact plate 9st, conductorglDQ and-actuating coil of switclr2-1to,negat7ive conductor Therefore, while (thec act-uatiou oftlie. toggle switch 4st effected through the, acceleration-of the engine .10, interrupts one actuatingcircuit of the s \\'itcl1 ,.24,;it establishes,another, and thereby theenergizationof .the field windings of the generator =14 .is continued. a

,Since the engine 10 is now operating at rated speed, the generator l-l builds up a voltage greatly in excess of that generated when the engine was operating at idling speed and the increased voltage issutticie'nt to actuate the rela.y. 8l., .As ,willbe observed by reference to 2,.the5relay84 is co n ,nected across. ,the line conductors 56, and current. now flows from line (conductor 55 through conductors 97;;rnd 103,;eo nt aet lingers 104 and 105, bridged by contact member 106, conductor 107, act-uilting-coilof relay 84., and conductors 108 and 109 to the negative line conductor 56. Upon. these-tuat-ion of relay 84, current, will flow from energize-d conductor 97 through a resistor 110, the actuating coil of the relay 84 and conductors 108 and 109 to line conductor 56. In this manner the relay is retained in its raised position and a resistor is insert-ed in t-heactuating circuit to preventan excessive flow of current which might be injurious to the relay coil. 1

It. will be noted that when the relay is actuated, contact member is moved into engagement with contact fingers 111 and 112 and .an actuating circuit for the switch 85 is established, which extends from energized condu ctor 87 through conductor 113, contact lingers 111 and 1 12, bridged by contact-member 90, conductor, 114, actuating coil of switch 85 and conductor96 to negative conductor {itii l \Vhen switch 85 is closed,a circuit is established from positive line conductor 55 through conductors 97 and-115, switch 85, conductor 116, the high-voltsge-armature 30 and tield winding '31, and conductors 98 and 109 to negative line conductor 56. [It will be understood that theaotuation oi thegovv ernor switch 41 will serve to make and break the actuating circuit of the switch 85, thereby -.mal(ing and breaking the operating circuit of the high-voltage windings of the motor 29. v

If, for any reason, the throttle 11 is act-u ated to decelerate-the engine 10, the voltage. across the qgenernton 14 .imi'nediately ;decreases,.a nd.t-hq,noltagerelay v55 permits the 1 contact member 90.to dro.p. Y In thismanner, provision .is made xior disconnecting the high-voltage windings ofzthe motor 29 from .the genoratorupon a decrease in the genercited 7. voltage H the governor switch is closed t-he lowsvoltage windings willcbe immediately.connectedacross the generator in .a nia-imer,hereinbefioredescribed From the toregoingdescript-ion it :willlbe evident-theta simple." system has devised for, changing the connections-pf the hi gh yoltage I and filmy-voltage, windings in accordance with the speed ;of theiengine, 10. $1 L l l Cllunges maybev Ina-dein'the above construction and. ,di'fierent :ernbod-iments of the inyention maybemade without departing. from the scope thereof, it; is intended-that all, matter containedinthe above description 1 1' shown in the accompanying drawing,l shi;ll be interpreted-as illustrative o and 119cm i1; limiting sensel .n

m-esm'y'i wen i n I li e-sass @e mpwer y n emb i nation, an, internal'fcornbustion enginei a generator driven-"hy said engine. whereby the generated voltage-varies with the engine speed, we" compressor ,motor (lisposedrto be cpnnected tof. the generato and, provided with high-voltage low-voltage wincL ings, and Jneanscoiitro'lled by 'thei generated voltage for selectixiely connecting the motor windi ngs) to ft-he generator.

2. Integers-electric power system, in combination, an iinterualcombustion engine. a generator driven by said engine whereby the generated voltage varies with the engine speed, a compressor motor disposed to be connected to the gener-ator and provided with highfivol'tage and low-voltage windings,

.and a voltage relay-connected acrossthe 'gcnerator and disposed to select-ively connect the motor wind'i ngsto the generator. i

3. Inagas-electric power system, combination, an internzil combustion engine, a fuelf'control throttle for regulating the fuel supply to varyv the speedof the engine, a genei-ator 'driven' by said engine whereby the generated voltageyaries with. the engine spe'edfa compressor 'motor provided with high-voltage and low-voltage windings disr s t l qimect i th genere tereen means dependent upon the g'hera'ted'fvoltage for selectively connecting the' motor'w1ndings to the generator. 4. In a gasfele'ctrie power system, in comvUh bination, an internal combustion engine, a fuel-control throttle for regulating the fuel supply to vary the speed of'the engine, a generator driven by said engine whereby the generated voltage varies with the engine speed, a compri-ssm motor provided with high-voltage and low-voltage windings disposed to be connected to the generator, means dependent upon the generated voltage l'or selectively connecting the motor windings to the generator, and means adapted to be actuated by the throttle for governing the circuit of the high-voltage motor windings.

5. In a gas-electric power system, in combination, an internal combustion engine, a fuel-control throttle for regulating the fuel supply to vary the speed of the engine, a generator driven by said engine whereby the generated voltage varies with the engine speed, a compressor motor provided with high-voltage and haw-voltage windings disposed to be connected to the generator, switches for connecting the compressor motor windings across the generator, actuating circuits for the switches, and a voltage relay connected across the generatormfor controlling the switch-actuating circuits to selectively connect. the motor windings to the generator.

G. In a gas-electric system, in combination, an internal combustion engine, a generator driven by said engine whereby the generated voltage varies with the speed of the engine, high-voltage and low-voltage motor windings disposed to be connected to the gen orator, an air compressor driven by the motor windings, means dependent upon the generated voltage for connecting the highvoltage and low-voltage motor windings to the generator, and means operable by the developed air pressure for governing the motor circuits.

7. In a gas-electric power system, in combination, an internal combustion engine, a generator driven by the internal combustion engine whereby the generated voltage Will vary with the engine speed, a compressor motor proy'ided with high-voltage and lowvoltage windings disposed to be connected across the generator, an air compressor disposed for operation by the motor windings, means dependent upon the generated .Voltage for selectively connecting the motor Windings to the generator, and means subject to the air pressure developed by the air compressor for governing the connections of th motor windings across the generator lndependently of said selective means for connecting the motor windings to the generator.

8. In a gas-electric power system, in combination, an internal combustion engine, a fuel-control throttle for regulating the fuel supply to the engine to vary its speed, a

generator driven by the engine whereby the generated voltage will depend upon the speed of the engine, a motor provided with high-voltage-and low-voltage windings disposed to be connected across the generator, a eon'ipre'ssor driven by the m0tor, means dependent upon the generated 'voltagefor selectively connecting the motor windings across the generator, and means adapted to be actuated by the fuel-control throttle for governing the connections of the high-voltage motor windiiws thereby to effect a dis connection of the ugh-voltage motor windings from the generator when said fuel control throttle is actuated.

9. In a power system, in combination, a prime mover adapted for operation at different speeds, a generator actuated by the prime mover whereby different voltages are generated when the prime mover is operated at different speeds, an auxiliary device which functions efliciently at substantially rated speed, a plurality of driving units for the auxiliary device, said units being adapted for operation at different voltages, and means for selectively connecting said driving units to the generator when the generated voltage varies a predetermined amount.

10. In a power system, in combination, a prime mover adapted for operation at different speeds, a generator provided with a diflerential field winding and disposed to be driven by the prime mover, the voltage of the generator varying with the engine load and speed, an auxiliary device which functions efliciently at a substantially rated speed, means adapted for operation at voltages below a predetermined value for actuating the auxiliary device, means adapted for operation at voltages above a predetermined. value for actuating the auxiliary device, and means sensitive to the generator voltage for selectively connecting an operating means for the auxiliary device to the generator.

11. In a power system, in combination, a prime mover adapted for operation at different speeds, a generator provided with a differential field winding and disposed to be driven by the prime mover, the voltage of. the generator varying with the engine load and speed, an auxiliary device which functions efiiciently at a substantially rated speed, means adapted for operation at voltages below a redetermined value for actuating the auxiliary device, means adapted for operation at voltages above a predetermined value for actuatin the auxiliary device, means sensitive to the generator voltage for selectively connecting an operating means for the auxiliary device to the generator, and means controlled by the voltage of the generator for selecting the actuating means for the auxiliary device.

12. In -a power system, in combination, a driven generator which develops a variable voltage nn'mrxiliary device which functions efficiently at substantially rated-speed, u.

5 plurality of driving units for the auxiliary device, said units being adapted foroperatio'n-at'difierent voltages, and means for momma selectively connecting said driving units to the generator :when the generated voltage varies a predetermined amount.

'In: 'testi'mony whereof, I have hereunto subscribed my name-this 11th day of Febr'ua'ry, 1-927 i ANDREW H. CANDEE. 

